1. Field
The present invention relates to a light emitting device and, more particularly, to a light emitting device having improved current dispersing performance and luminous efficacy, and a method of fabricating the same.
2. Discussion of the Background
Generally, a light emitting device includes an N—GaN layer, an active layer and a P—GaN layer, which are sequentially formed on a substrate such as a sapphire substrate, a p-electrode formed on the P—GaN layer, and an n-electrode formed on the N—GaN layer.
The n-electrode is formed on a portion of the N—GaN layer, which is exposed by partially etching the active layer and the P—GaN layer.
In addition, a transparent electrode layer is formed on the P—GaN layer. The transparent electrode layer is formed to achieve uniform spreading of electric current on the P—GaN layer having very high resistance.
The light emitting device is operated by connecting an external power source to the p-electrode and the n-electrode, such that light is generated in the active layer. Although some of the light generated in the active layer is emitted outside, a substantial amount of the light may be absorbed by the sapphire substrate and semiconductor layers, causing optical loss. In particular, a high index of refraction of the GaN layer may cause total internal reflection at a surface of the GaN layer, causing loss of light inside the GaN layer instead of allowing emission of light to the outside.
Recently, a light emitting device capable of being operated by a high electric current of 1 A or more has been developed. Upon operation of the light emitting device under high current conditions, the light emitting device may suffer from severe current crowding. Therefore, there is a need for a light emitting device having improved current dispersing performance.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form any part of the prior art nor what the prior art may suggest to a person of ordinary skill in the art.